将 EVENT 范围的 bean 注入到 CONVERSATION/SESSION 范围的 bean 中是否更安全？

Question

Is it safe to inject beans from narrower scope into a wide scoped bean?

Does Seam CDI take care of it to figure out current EVENT/REQUEST/PAGE context to do the right injection into SESSION/CONVERSATION bean.

My point is. I don't want one page/even's objects getting mixed up with other page/event's data.

I can always use Component.getInstance() within the method to make sure I get current event/page's beans anyway. But I would like to use @In(scope = ScopeType.EVENT) even for this.

Answer 1

Session and page scoped components are synchronized per default. Therefore, it should be safe to inject an event-scoped component, such as EntityManager , into them. As it is synchronized, two request won't interfere with two different injected objects.

To be completely sure, that you don't run into concurrency problems, I recommend that you don't inject these components but fetch them from the component repository:

MyComponent myComponent = (MyComponent) Component.getInstance("myComponent");